The present disclosure relates to subject matter contained in Japanese Patent Application No. 10-31043 (filed on Feb. 13, 1998), which is expressly incorporated herein by reference in its entirety.
1. Field of the Invention
The present invention relates to a cytologic brush for an endoscope which has a brush member attached to the distal end of a sheath that is removably inserted into an instrument-inserting channel of the endoscope. More particularly, the present invention relates to a cytologic brush for an endoscope that is designed so that the direction of the brush member can be changed by remote control from the proximal end of the sheath.
2. Description of the Prior Art
Cytologic brushes for endoscopes are widely used to perform a scraping cytodiagnosis, in which cells are collected from the mucous membrane surface of a bronchial tube or the like. A typical cytologic brush has a brush member attached to the distal end of a sheath that is removably inserted into an instrument-inserting channel of an endoscope.
There are conventional cytologic brushes arranged so that the direction of the brush member can be changed by pulling a control wire, which is connected to the brush member and inserted in the sheath, from the proximal end of the sheath, thereby enabling a cell collecting location to be selected as desired.
In all the conventional cytologic brushes that can be reoriented, the direction of the brush member is changed by bending the distal end portion of the sheath. During the reorientation of the brush member, the control wire, which is inserted in the sheath, is also bent together with the sheath. Therefore, in the course of using the brush repeatedly, the control wire develops an undesired bending habit. Consequently, the brush member becomes incapable of extending straight ahead and hence difficult to use.
The conventional cytologic brushes further have the disadvantage that the direction of the brush member can be changed in only one direction from the extension direction of the axis of the distal end portion of the sheath (i.e. from a position where the brush member extends straight ahead). Therefore, in a trifurcated deep bronchial tube as shown in FIG. 8 by way of example, a brush member 20 projecting from the distal end of an endoscope 50 can be inserted into either of two tubes, i.e. one that lies in front of the brush member 20, and another that lies in a direction to which the brush member 20 can be deflected. Thus, the inspection range is unfavorably limited.